The present invention relates to an ingredient and a method of providing an acid environment in baked goods. More particularly, the present invention relates to an encapsulated acid which provides an acid environment to a baked bread product without deleteriously affecting the bread dough before baking.
The preservation of certain food products entails the provision of an acidic environment to the product to provide stability against microbiological contamination. An acidic environment in foodstuffs has been found to act synergistically with an antimicrobial package of ingredients (such as, but not limited to, calcium propionate, sorbic acid, and benzoic acid) to increase shelf life. This is especially important when dealing with baked goods, which enjoy a longer shelf-life at a lower pH. Food grade acids are typically used in baking formulations to provide an acidic environment to a baked good.
Wheat flour tortillas which are produced for food service and packaged sales must be prepared to meet extended shelf life standards. The shelf life of wheat flour tortillas can be increased through the use of antimicrobial ingredients such as sorbic acid, calcium propionate, and sodium benzoate. In order to stabilize the antimicrobial properties of these ingredients, the pH should be kept in the acidic range, and it has been found that a pH of between about 6.0 and about 5.5 is a particularly desirable pH range for preserving baked goods.
The incorporation of food grade acids, however, presents problems for baked goods. When food acids are added to bread they have a negative effect on the proteins (gluten) in the bread, as well as the chemical leavening system. Gluten is a mixture of many proteins. The elasticity of gluten is influenced by pH. At a neutral pH, the proteins can be stretched and they will hold their shape. The degree to which the gluten can be stretched and still maintain its shape is defined as "extensibility." Gluten in a more neutral state will be more extensible, in that it will better hold its shape when stretched. Dough with a neutral pH is more easily deformable, can be stretched further, and more easily retains its stretched shape. Acidified gluten, on the other hand, is more elastic, less extensible, and will stretch, but it tends to return to its initial shape. As dough becomes less extensible, more energy is required to form and maintain the shape of the dough. The energy imparted can be by additional mixing, kneading and machining, increased pressure, or higher processing temperatures. Furthermore, because the dough is more likely to recoil, a finished product is usually a denser size per mass of the dough. Thus, a tortilla resulting from a more acidic dough will have a smaller height and diameter.
The addition of preservative acids to bread dough can also have a negative effect on the bread leavening, system. Chemical leavening systems usually include a food grade acid, eg., sodium acid pyrophosphate (SAPP), sodium aluminum phosphate (SALP), mono calcium phosphate (MCP), and a base, e.g., a carbonate source (generally sodium bicarbonate), which react to form carbon dioxide which is then trapped in the cell walls of the bread to leaven the mass. In most leavened products the base (sodium bicarbonate) dissolves in the dough while the acid portion does not go into solution until the dough is subjected to temperatures above 100 degrees Fahrenheit This prevents the formation of carbon dioxide until the dough cell walls are prepared to expand and trap the gas. When acid is added for preservation, however, it dissolves at the initial stages of mixing, and begins to react immediately with the dissolved sodium bicarbonate. The formation of carbon dioxide therefore occurs prematurely. During the baking stage, when leavening gases should be produced, the sodium bicarbonate is already fully reacted. This results in bread which is not fully leavened. Premature leavening leads to many undesirable physical qualities in the finished bread product.
A further negative effect which occurs as a result of the dough having acidic properties is that the capacity of the dough to hold water is decreased. Water migrates out of acidic dough and moves toward the surface. This causes the dough to become sticky, resulting in adherence to processing equipment. Moreover, breads which require molding or shaping are adversely affected by sticky dough because the desired shape will not be obtained in the raw dough. Thus, the shape of the finished bread product tends to be unpredictable and irregular. The overall effect of an acidic bread dough is to reduce the yield of product, produce an irregularly-shaped baked good, and increase costs of production.
In order to avoid some of the problems associated with prematurely acidifying bread dough, fumaric acid has been commonly used as a preservative acid because of its low solubility. The advantage of using an acid with low solubility is the delay in dissolution during mixing and baking. If a low pH is avoided during this time, the deleterious affects set forth above are reduced.
In spite of its low solubility, raw fumaric acid still dissolves prior to baking and lowers the pH of the bread dough sufficiently to reduce the dough's machinability; i.e., the dough loses extensibility and recoils after flattening and lengthening. Negative effects can be seen in the finished product. In the case of tortillas, translucent spots appear in the tortilla, and pillowing which is a separation of the skin, occurs. Furthermore, raw fumaric acid causes an increase in stickeness of tortilla dough. This results in a baked product which has poor crumb texture. Furthermore, the tortilla product is somewhat small in diameter per dough mass because of the recoiling of the dough.
In the interest of reducing solubility, artisans used large particle sizes of fumaric acid. As with any solute, the particle size is inversely proportional to its solubility, i.e., the larger the particle size-the slower the rate of dissolution. (Conversely, the smaller particle size-the quicker the rate of dissolution). In order to further reduce solubility of fumaric acid, it is also known to coat the fumaric acid with a coating which further delays the dissolution.
Even the large size particles, e.g. on the order of 300 microns, however, fail to achieve the desired time-dissolution profile for dough formation and baking. When the total of fumaric acid required is provided in large particles, more particles are required to achieve the required early post-baking pH, and this problem is exacerbated when coatings are used. The total amount of fumaric acid therefore must be increased to a level which causes unwanted pre-baking migration into the dough causing the previously discussed harmful effects.
It is also known to add food grade acids, particularly fumaric acid, into bread dough to impart a sour taste to a finished bread product. This is especially prevalent in baking sourdough bread compositions. U.S. Pat. No. 3,922,350 to Dockendorf discloses an acidified bread dough suitable for preparing sour dough bread which includes an amount of fumaric acid sufficient to lower the pH of the baked bread to between about 4 and 5. Dockendorf coats the acid with an edible material, and uses large size fumaric acid particles on the order of approximately 300 microns diameter. As in other cases previously described, Dockendorf must add a large amount of coated fumaric acid to the dough.
It is most preferred, therefore, to provide a fumaric acid particulate in bread doughs which remains undissolved prior to baking to provide a neutral pH. The food acid should then dissolve substantially completely during baking, to adjust to a stable acid pH range of between 6.0 to 5.5 within about 15 minutes of baking. This pH should remain substantially stable throughout the shelf-life of the bread or tortilla, i.e., there should be no undissolved acid which subsequently dissolves to lower the pH. This pH has been found as the optimum pH to preserve antimicrobial ingredients and increase shelf life of a baked good.
Previous attempts to coat fumaric have been unsuccessful in producing a desirous product in large part because of the large particle size of the fumaric acid used. An increased amount of fumaric acid was required to be added to the composition in order to provide its desired effect For example, raw fumaric acid was typically added to bread dough compositions at about 0.1% to about 0.7% based on flour weight. With previously coated fumaric acid particulates, it was required to add 1.0% to about 3.0% by weight of fumaric acid based on flour weight in order to achieve the satisfactory pH range.
It is therefore, an intention of the present invention to provide, among other things, an improved fumaric acid ingredient for providing an acid environment to bread dough formulations without deleteriously affecting the baked good product.